Method of crimping and insulating an electrical terminal



Nov. 9, 1965 E. FLOYD, JR 3,216,091

METHOD OF CRIMPING AND INSULATING AN ELECTRICAL TERMINAL 2 Sheets-Sheet 1 Original Filed Sept. 25, 1955 {dwn f/oqd) J7? BYM,WW 1- SAW E. FLOYD, JR

Nov. 9, 1965 METHOD OF CRIMPING AND INSULATING AN ELECTRICAL TERMINAL 2 Sheets-Sheet 2 Original Filed Sept. 25, 1955 INVENTOR. dw1'n floyd, zfr. "amm, MM SW United States Patent O 3,216,091 METHOD F CRIMPING AND INSULATING AN ELECTRICAL TERMINAL Edwin Floyd, Jr., Harrisburg, Pa., assignor to AMP Incorporated, a corporation of New Jersey Application Aug. 18, 1959, Ser. No. 834,489, which is a division of application Ser. No. 536,127, Sept. 23,

1955, now Patent No. 2,930,836. Divided and this application Aug. 13, 1962, Ser. No. 216,610

2 Claims. (Cl. 29-155.55)

This application is a division of application, Serial No. 834,489, filed August 18, 1959, now abandoned, based on parent application, Serial No. 536,127, filed September 23, 1955, now Patent No. 2,930,836.

An electrical circuit is no better than its most vulnerable part. Like any other transmitting means, a flaw in one section will reduce the eiciency of the entire component to the level of the imperfect part. Thus, when engineering a complex guided missile, rocket, airplane, or artificial astral body, etc., the circuit supplying the current to the components is the arterial network supplying the lifes blood to the system. The junctions of these currentladened conductors are indeed vulnerable areas of the device. A suitable connection, performance-wise, must be secured to a degree that will withstand the extreme vibrations typically present in devices of the class described. In addition, the connection must be highly conductive approaching the conductivity of the conductor as a desideratum. In addition, it is often necessary to provide an insulation for the connection. Properties of the insulation include high heat resistance, durability, inertness to a variety of chemicals and solvents with which it may come into contact, and, of course, good dielectric properties. From a manufacturing standpoint, the connector should be easily applied and inexpensive to manufacture.

With these factors in mind, it is an object of this invention to provide a connection that will combine to the maximum the features set forth above with special emphasis on the ability of the insulation to withstand high temperatures. Using the insulated connector set forth in this application, it is possible to provide an insulation that will withstand greater temperatures than the conductor itself.

It is also an object of this invention to provide a connector capable of being insulated with ceramic or glass, as well as other types of standard insulating sleeves.

It is a further object of this invention to provide a means for crimping a connector onto a conductor in such a manner as to make a secure, efficient connection, and at the same time provide a means for securing an insulating sleeve thereto.

Another object of this invention is to provide a set of dies that will crimp a connector onto a conductor in such a manner that a strong, efficient connection is made, as well as providing a lock means for securing an insulating sleeve to the connection.

Other important features and objects of the invention to which reference has not been made hereinabove will appear hereinafter when the following description and claims are considered with the accompanying drawings, in which:

FIGURE l is an exploded view of an improved connector embodying the principles of this invention;

FIGURE 2 is a perspective view of the improved connector prior to securing a conductor;

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FIGURE 3 is a perspective view of the connector of FIGURES 1 and 2, with a conductor cold-forged thereto, showing the insulating sleeve in a retracted position;

FIGURE 4 is a plan view of the improved connector with a conductor secured in place;

FIGURE 5 is a sectional View taken through plane V-V of FIGURE 4;

FIGURE 6 is a sectional view taken through plane VI-VI of FIGURE 5;

FIGURE 7 is a side view of the connector shown in FIGURES 1-6, with a conductor secured in place and the insulating sleeve partially retracted;

FIGURE 8 is a sectional view taken through plane VIII-VIII of FIGURE 7;

FIGURE 9 shows a connector illustrative of the invention, particularly adaptable to securing two wires together;

FIGURE 10 is a View of the connector shown in FIG- URE 9 with the insulation sleeve retracted, demonstrating how the connector is applied to the Wires;

FIGURE l1 is a diagrammatic view showing the relationship of parts between the connector, the conductor and the crimping dies;

FIGURE l2 is a perspective View of the crimping dies;

FIGURE 13 is an end view of the crimping dies; and

FIGURES 14 and 15 show other modifications of connectors incorporating principles of the invention having different means for locking the sleeeve in place.

As shown in FIGURE l, the preferred embodiment of the improved insulated connector is made in three pieces. A tongue member 10 has an opening 12 for securing the tongue to a binding post to permit transference of electricity. A ferrule 14 forming one end of tongue 10 is secured to an intermediate sleeve 16, and an insulating member 1S surrounds the assembly. The insulating member 18 is tubular and may be made from ceramic (such as steatite), glass, Bakelite or any like material with good electrical, insulating properties. The advantage of using ceramic or glass is that these materials combine the properties of good electrical insulation and high heat resistance.

As shown in FIGURE 2, the insulating sleeve has an inner iiange Z0 which encompasses the outer surface of intermediate sleeve 16 but permits the insulating sleeve to move longitudinally relative to the intermediate sleeve. A pair of slots 22, 22 are provided at diametric positions on llange 20 for reasons to be discussed later.

The conductor C is secured to the connector by crimping the intermediate sleeve to the conductor by use of a pair of crimping dies as shown in FIGURES 12 and 13.

The particular dies shown in the drawings are comprised of a pair of V-shaped members 30, 30 which constitute an upper and lower die means respectively. Extending outwardly from each of the free ends of the V is a flat surface 32. The flat surfaces 32 of one die oppose the surfaces 32 on the other die, as shown in FIGURE 12. One of the die means fits inside the other, .and abutments 34 prevent opposed surfaces 32 from contacting each other when the dies are closed. Thus, when the dies are closed on a connector with a conductor located therein, the connector and conductor are deformed into the shape of a square, as seen in cross-section (see FIGURES 8 and 11), with a pair of lugs 36, 36 extending from opposite sides of the connector. As shown in the drawings, two sets of dies are provided. One set acts to crimp the connector to the conductor, whereas the second set crimps the connector to the insulation sheath covering the conductor.

Spacer plates 36 are provided between 4each set of dies. However, it is evident that the dies might be extended to crimp the connector and the insulation, instead of being made in two longitudinal sections. Additional plates 38, 40 are provided on each end of the dies to act as confining plates, The upper and lower plates nest one within the other, as shown in FIGURE 12. Screws 42 extend through the assembly to secure the dies and plates in their respective operative positions.

When applying the connector to the conductor C, the insulation sheath is stripped from one end of the conductor to expose a bare portion of the conductor. The connector is assembled, as shown in FIGURE 2, with ferrule 14 within sleeve 16 and insulating member 18 surrounding sleeve 16. Flanges 19, 19 on each end of sleeve 16 limit the travel of the insulating member 13 relative to sleeve 16 between the position shown in FIG- URE 2 and the position shown in FIGURE 8.

With the assembly in the position shown in FIGURE 2, the conductor C is inserted within sleeve 16. The bare end of the conductor will extend through ferrule 14 and the insulation will abut against the rear end of the ferrule (see FIGURE thus acting as a positioning means. When the bare end of the conductor extends part-way through ferrule 14, the operator can be assured that the conductor and ferrule are in proper position.

When the conductor is positioned within the ferrule, the crimping dies are applied across the sleeve, thereby crimping the ferrule onto the bare end of the connector and the sleeve onto the insulation (see FIGURE 5). As shown in FIGURE 11, the connector and conductor are deformed from the dotted-line position to the full-line position. A pair of lugs 36, 36 are thus formed on sleeve 16 in a position whereby they mate with slots 22 in flange 20.

After the connector is crimped to the conductor, as shown in FIGURE 3, insulating sleeve 18 is moved forwardly relative to sleeve 16, lugs 36 engaging slots 22. The flange 19 on sleeve 16 limits forward travel of the insulating sleeve. In this position, sleeve 16 is wholly within insulating member 18 and the two are free to rotate relative to each other since lugs 36 no longer engage slots 22.

The sleeve 16 is then rotated relative to insulating member 18 so that lugs 36 are no longer aligned with slots 22. This, in effect, serves to lock member 18 in place relative to sleeve 16. A bayonet-type connection may be provided to prevent inadvertent unlocking of these members.

The insulating member 18 may be subsequently disengaged from sleeve 16 by realigning lugs 36 with slots 22, again permitting relative longitudinal movement. However, accidental realignment is prevented by frictional contact between ridge 19 and the front edge of the insulating member.

The modification shown in FIGURE provides an additional means of preventing accidental relative rotation of insulating member 18 and sleeve 16 through the medium of tabs 44 which are cut from ridge 29. These tabs are bent inwardly to engage recesses 46 in the one end of the insulating member. Thus, the frictional engagement between tabs 44 and recesses 46 tends to prevent relative rotation therebetween. Also the inner crosssectional configuration of the insulating sleeve may be slightly elliptical, with the major axis extending along the plane of slots 22. When sleeve 16 is rotated to a locking position, i.e., 90 from the position shown in FIGURE 5, lugs 36 are wedged within the insulating sleeve along the minor axis of the ellipse. This provides a tight frictional engagement between the lugs and the inner surface of the insulating sleeve.

FIGURES 9 and 10 show a butt connector used for splicing two or more wires together in an end-to-end engagement which embodies principles of the invention.

An inner metal ferrule 60 is open at each end. A metal sleeve 62 is secured to the ferrule so that the ferrule is located centrally within the sleeve. The ferrule and sleeve have a central opening to permit inspection. The edge of the opening in the sleeve is turned inwardly to secure the ferrule in place. Furthermore, the opening in the sleeve operates as a reference point in determining where the crimps should be made.

An Outside insulating member 64 surrounds sleeve 62 and is relatively slidable with respect thereto. A flange 66 extends inwardly from insulating member 64. This fiange may be integral with the insulating member or formed as a separate member which is secured in place within the insulating member. Flange 66 has the same cross-sectional configuration as flange 20 set forth in the embodiment of FIGURES 1-3, i.e., the circumference of the opening in the flange is slightly greater than the outside circumference of sleeve 62, and a pair of slots are provided at diametrical positions on the flange. The sleeve 62 is flared outwardly at each end, as at 66', to

permit it to telescope relative to the insulating member but prevent disengagement of the two members.

The method of applying the butt connector to the conductors is similar to the method of applying the connector of FIGURES 1-3 to a conductor. As shown in FIGURE l0, sleeve 62 is extended so as to be accessible to crimping dies A and B. The conductors are placed within sleeve 62 with the bare ends extending into ferrule 60. The ferrule 60 will accommodate the conductor but not the insulation, thus acting as a positioning means. A slot 68 is provided in the ferrule and sleeve to permit inspection, thus assuring proper positioning of the conductor prior to crimping. With the conductor properly in place, crimping dies, of the type shown in FIGURES 12 and 13, are brought to bear upon sleeve 62. The dies, designated A, deform the sleeve and ferrule onto the conductor. The dies, designated B, crimp sleeve 62 onto the insulation. The particular crimp employed forms lugs on the sleeve which mate with the slots formed in flange 66. After the crimp is effected, sleeve 62 is telescoped back onto insulation member 64, and rotated into locking position in the same manner as employed in the case of the connector of FIGURES 1-3.

The embodiment set forth in FIGURE 14 is similar to that shown in FIGURES 1-3. However, the connector shown in FIGURE 14 has an inner metallic sleeve 70 bonded to an insulating member 74. One end of this sleeve is formed in a shape similar to the shape of the cross-section of the crimp, as at 72. This serves the same purpose as ridge 20 with slots 22 of FIGURES 1-3. After a conductor is crimped onto a ferrule and protruding lugs are formed diametrically thereon, the connector is inserted into the insulating member by aligning the ferrule with the end of sleeve 72. After the ferrule is within the sleeve, it is rotated out of alignment, thus preventing disengagement.

It is noted that the outer layer of insulation may be applied by coating a metal sleeve with a glaze, such as used on ceramic work. This coating of glaze may be sprayed, brushed or dip-coated onto the sleeve.

Changes in construction will occur to those skilled in the art and variously apparently different modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only. The actual scope of the invention is intended to be dened in the following claims when viewed in their proper perspective against the prior art.

I claim:

1. A method of connecting a connector to an electrical conductor and to effect an insulated connection thereof comprising the steps of (l) crimping said connector onto said conductor and simultaneously therewith providing lugs extending outwardly from said connector; (2) moving an insulated sleeve provided with an inturned flange having slots disposed therein corresponding to the position of said lugs along said connector and to encompass said lugs beyond said ange; and (3) adjusting said insulated sleeve relative to said connector until said lugs and slots are out of correspondence to secure said insulated sleeve on said connector.

2. In a method for connecting a connector element to an electrical conductor and to effect an insulated connection thereof: (l) disposing said electrical conductor on a crimping area of said connector element; (2) crimping said crimping area onto said conductor to provide a mechanical and electrical connection therebetween and to form lug portions on said connector elements; (3) sliding an insulated sleeve member provided With an inturned flange having slots therein mating With said lug portions along said connector element to encompass said lug portions beyond said ange; and (4) moving said insulated sleeve member relative to said connector ele- 6 ment so that said lug portions and said slots are out of mating position to secure said insulated sleeve member and said connector element together.

References Cited by the Examiner UNITED STATES PATENTS 2,257,317 9/41 Wade 339-205 2,279,794 4/42 Olson 29-155.55 X 2,316,267 4/43 McLarn 174-84.1 2,589,368 3/52 Graham et al. 339-213 2,596,528 5/52 Carlson 29-155.55 X 2,603,679 7/52 Pavlinetz 339-213 2,729,695 l/56 Pierce l74-84.1 2,817,698 12/57 Schneiderman 174-5 2,872,505 2/59 Ustin 174-87 WHITMORE A. WILTZ, Primary Examiner.

JOHN F. CAMPBELL, Examiner. 

1. A METHOD OF CONNECTING A CONNECTOR TO AN ELECTRICAL CONDUCTOR AND TO EFFECT AN INSULATED CONNECTION THEREOF COMPRISING THE STEPS OF: (1) CRIMPING SAID CONNECTOR ONTO SAID CONDUCTOR AND SIMULTANEOUSLY THEREWITH PROVIDING LUGS EXTENDING OUTWARDLY FROM SAID CONNECTOR; (2) MOVING AN INSULATED SLEEVE PROVIDED WITH AN INTURNED FLANGE HAVING SLOTS DISPOSED THEREIN CORRESPONDING TO THE POSITION OF SAID LUGS ALONG SAID CONNECTOR AND TO ENCOMPASS SAID LUGS BEYOND SAID FLANGE; AND (3) ADJUSTING SAID INSULATED SLEEVE RELATIVE TO SAID CONNECTOR UNTIL SAID LUGS AND SLOTS ARE OUT OF CORRESPONDENCE TO SECURE SAID INSULATED SLEEVE ON SAID CONNECTOR. 